STEEL TUBE AND PIPE HANDBOOK - February 2012

13 Continuously cast steel blooms Steel blooms are the starting material for the production of seamless hot finished tubes and pipes. They are also used for the production of other metallurgical semi products by hot forming (rolling, forging, pressing). Dimensions and tolerances Blooms of square cross-section * Difference of diagonals of square Blooms of circular cross-section Lengths The blooms are delivered in lengths of 4000–9000 mm with length tolerance of +50 mm. Straightness tolerance - 1% of length Obliqueness of front side - 5° Steel quality The steel is produced by electric process and is fully killed. The chemical composition of the steel is determined by standards and steel grades for individual groups of tubes. It is also possible to deliver blooms from other steel grades to meet specific customer require- ments. Element content in % of weight C Mn Si Cr Mo Ni V S P Cu Sn Al Ti B Nb O N min 0,05 0,3 0,1 0,05 0,05 max 0 max max max max 0,005 max 1,2 2,5 1,3 2,5 1,1 3,4 0,8 0,035 0,035 0,40 0,040 0,050 0,050 0,001 0,050 0,00035 0,010 Heat treatment, delivery condition and surface quality After casting the blooms are not heat treated, nor is the surface treated. Blooms are delivered according to technical delivery requirements. Testing Blooms are tested according to appropriate standards. Marking Blooms are stamped on their face. Markings include: heat number, steel grade code, stream number. In special cases blooms are marked with colour. Laying of blooms Square cross-section – in layers Circular cross-section – in special wooden pads or bound with steel strip. Certification Test report certificate in accordance with the specification: DIN 50049, EN 10204 – 2.2 or others. Gases volume: O max. 0,00035% (3,5ppm), H max. 0,0050% (50ppm), N max 0,010% (100 ppm) - according agreement max. 0,008%. Conversion: a (%) x 10 000 = b (ppm). (But the using of ppm is in system SI non-permissible). 125 ±3 5 15 600 121,9 R = 2 mm ±1 mm 150 ±3 6 22 420 175,5 R = 5 mm ±1 mm 160 ±3 6 25 600 199,7 R = 10 mm ±1 mm 180 ±3 7 32 100 252,7 R = 10 mm ±1 mm 200 ±4 7 39 680 312,0 R = 10 mm ±1 mm 225 ±5 9 50 170 394,8 45 ° /15 mm 280 ±8 11 76 662 598,0 R = 45 mm ±1,5 mm Square side Tolerances Sidelong max* Cross-section area Weight Edge of the bloom [mm] [mm] [mm] [mm 2 ] [kg/m] [mm] Diameter Tolerances Ovality Cross-section area Weight [mm] [mm] [mm] [mm 2 ] [kg/m] 150 ±2 3 17 662 137,7 180 ±3 5 25 434 198,4 210 ±4 5 34 618 270,0 240 ±4 6 45 216 352,7 260 ±5 6 53 066 414,0 280 ± 5 7 61 575 480,0